the girl is under the age of consent, but looks older and lies to the boy

This seems chiefly non-consensual for the boy, and it's certainly not justified to put him at risk of prosecution!

The next case sounds bad to me, perhaps because the issue would never arise with adults if when the drug(s) wore off she recalled saying it and would still have said 'yes'. (Or I may be reading it with the knowledge that the law does not, practically speaking, forbid sex with someone who's had a few drinks.) But I technically agree that we'd need more information.